Adjustable Dado Jig
On my last project (Record Player Stand) I made a temporary jig to make stopped dados… so I got to thinking how I can make an adjustable dado jig that can be used for many different operations, and here it is!
All the fences on this jig are adjustable so you can make through dados, stopped dados, and even mortises!
Check out the video below to see how I put it all other and figured it out!
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Want plans for this jig? You can find them here:
Adjustable Dado Jig Plans
What you’ll need:
Plywood
Let’s Begin!
All router bases have different dimensions. Make sure to measure your router base to get the most accurate jig.
Mine is about 7” wide, so I needed each base piece to be at least 3-1/2” wide, plus the width of the T-Track , plus extra material for clamping.
Rip the plywood a little oversize at this point.
It will be flushed up in a later step. This measurement doesn’t need to be perfect or exact.
Cut the two base pieces to length based on the size T-Track you are using.
For this jig, you always have to use the same router bit. Make sure that bit is installed, then place your router on the plywood to get a location for where the T-Track fences will go.
You want to line it up so the router bit will take off a small amount of material when you first use it.
There is also a chance your router bit might be slightly off-center… so make sure to mark the side of the router and the base pieces with a symbol so you know which side of your router matches which side of the jig.
Repeat the same thing on the other side to create the two base pieces of the jig.
Now run the router along the T-Track fence to make it zero clearance.
When doing this, make sure the symbols you drew on the router correspond to the correct side of the jig.
The front and back fences will slide along the T-Track within a dado.
One dado is the exact width of the T-Track.
The other dado is wider so the main base pieces of the jig can slide right to left adjusting for different size materials.
Use the router with the correct bit installed to mark off where this dado should start.
Then slide the base piece to the max desired width you need for your projects to mark the other side of the dado.
Cut this dado however you like.
I like to use a Flat Top Grind blade at my table saw for pieces like this… The flat teeth make the bottom of the dado flat and smooth so you don’t need to clean it up with a chisel.
But a router table or miter saw with depth stop work as well…
Then rip the fence pieces to width.
These fences will be held in place using t-bolts and knobs, all of which I get from this Jig Hardware Kit. I love this kit…
Drill a hole for the t-bolt in the center of the dado that is the exact width of the t-track.
And make a slot in the wider dado.
Put the fences on the jig using the hardware and plunge the bit so it touches the edge of a scrap piece.
Make a mark on the bottom of the right-hand fence, this is where you will place the square stopper piece.
Lock down the square stopper piece with brads making sure it is truly square.
Then cut the alignment guides to size and install them under the fence.
These will make it so that you can easily line the fences up to a pencil line for stopped dados or mortises.
And it’s done!
To use the jig, all you need to do is use your material as a reference between the two base pieces and lock them in place!
Then run your router along the t-track guides to create the dado!
This will make a dado up to 24” long, longer if your router base plate is smaller…
You can also adjust both the front and back fences to make stopped dados in either direction.
And add on fences in the middle to cut mortises!
I love how there are so many different things this jig can do and I can’t wait to use it on my future projects!
